A comunidade de esfingídeos (Lepidoptera, Sphingidae) e plantas esfingófilas numa área de cerrado no sudeste do Brasil: biogeografia e associações mutualísticas

Abstract

Hawkmoths (Lepidoptera, Sphingidae) are among the major pollinators in tropical communities. However, in the Cerrado biome little is known about their distribution, species composition, diversity, as well as, their relationships with hawkmoth-flower plant flora. This study aim to describe the hawkmoth fauna and hawkmoth-pollinated plant flora of a Cerrado area in the Southeast of Brazil. We analyzed the biogeography pattern of species distribution in the Cerrado region and Neotropical area, evaluated its associations with sphingophilous plants testing the hypothesis of ecological fitting, and based on pollinic data, we described the mutualistic network pattern between hawkmoths and hawkmoth-pollinated plants. A total of 61 hawkmoth species was recorded for the study region, what represents more than a fifth of South America hawkmoth fauna. The species distribution was markedly seasonal. The Cerrado s hawkmoth fauna showed higher similarity with faunas from forest ecosystems in the Neotropics. The expected species richness for Cerrado region was comparable or even higher than those values expected for highly diverse regions as Atlantic forest areas. The match among hawkmoth proboscis lengths and corolla tube depth of hawkmoth-pollinated plants in a community level indicates an ecological fitting between these groups. The appearance of the hawkmoths with longest proboscis showed a phenological synchronization with flowering period of the most specialized hawkmoth-flower plants (those with the deepest corolla tubes). This suggests that there is also a phenological fitting between these interacting organisms. The mutualistic network among hawkmoths and their visited plants revealed a pattern highly nested. The Cerrado possess very high hawkmoth species richness and its composition is possibly influenced as much by historical factors, like species interchange among adjacent ecosystems occurred during the climatic-vegetational fluctuations in the Quaternary period, as for the occurrence of a constant species migration dynamic between different habitats. These processes possibly have strong implications on the ecological fitting between hawkmoths and plants. These mutualisms in conjunction to other selective pressures, such as the competition among hawkmoths for nectar, have allowed the evolution and establishment of interesting ecological patterns, like the phenological fitting between hawkmoth-plants and their pollinators.